Casing float collar



'May 17, 1938. D. HANES CASING FLOAT COLLAR Filed Jan. 9, 1937 e man INVENTOR. 7c-an Hanes. BY 5M/aww@ ATTORNEY Patented May 17, 1938 PATENT. OFFICE I CASING FLOAT C0 Dean lianes, Duncan, Okla., assigner to Halliburton Oil Well Cementing Company, can,

(llkla.

application January 9,

4 Claims.

This invention relates to casing float collars or shoes adapted for use in lowering casing into oil. wells or the like and in the cementing of the well..

It is desirable, when lowering a long string of pipe into a well. to maintain a seal in the bottom thereof so that the mud pressure or pressure of other iiuid in the Well will relieve the strain on the well equipment to some extent due to the buoyancy of the empty string. The use of float collars or float shoes for this purpose is well known to those skilled in the art. The present invention relates to a novel construction which` has certain advantages over the similar devices heretofore employed for the same purpose, the chief advantages of the -present construction' being the provision of a float collar or shoe which may be readily drilled out and which will yet maintain an effective seal at a desired point in the casing or pipe.

It is one object of the invention, therefore, to provide a float collar with a valve therein which is made of non-metallic parts so that it may be readily drilled out.

It is another object of the invention to provide a float collar with a valve and in which an effective seal is maintained around the valve seat.

Other objects and advantages reside in certain novel features of the construction, as will be apparent from the following description taken in connection with the accompanying drawing, in which:

Fig. l is a vertical cross-sectional view of a portion of an oil well with a casing and float collar constructed in accordance with the present 1nvention shown therein in vertical cross-section;

Fig. 2 is an enlarged Vertical cross-sectional view of the float collar shown in Fig. l; and

Fig. 3 is a transverse cross-sectional view of the float collar shown in Fig. 2, the view being taken on the line 3 3 of Fig. 2.

Referring to the drawing in detail, and first to the arrangement of Fig. 1, it will be seen that a well bore is there illustrated at I I. The lower end of one string of casing is shown at I2 and a portion of a second string of casing I3 is shown located Within the string I2. Thestring of casing I3` is provided with a float collar I4 constructed in accordance with the present invention.y

As shown. in Figs. 1 and 2, the float collar I4 is provided with threaded portions I5 and I6 at its upper and lowerends respectively, to provide means for attaching it to the sections of casing I3. The inside of the collar I4 has a number of' grooves I'I cut therein to aid in securing cement 193i, sensi ne. '1119.797 (er. 16s-e) or concrete plugs to the collar. Two concrete plugs are provided, the upper one of which is designated It and the lower one of which is designated I9. These plugs are molded into the steel collar ld in constructing the apparatus. The up- 5 per plug I8 is provided with a central fluid passage Zil, this passage being centrally disposed within the plug.

'Ihe lower plug I8 is preferably provided with several fluid passageways. Three such passage- 10 ways are shown in the` drawing at 2I and extend from top to bottom of this plug.

The lower plug I9 acts as a cage for the valve member .2 and for this purpose is provided with a centrally located pit 23. The plug I 9 is so mold- 15 ed that the pit 23 does not extend the full depth of theV plug but has a bottom portion 2li which prevents the valve member 22 from falling out of the collar. The pit 23 is connected to the pas sages 2i throughout its length, asbest shown in Fig. 3.

The valve member 22 is preferably made of hard rubber or bakelite and may be balbshaped, but is preferably cylindrical so as to be guided by the wall portions 25 around the pit 23 and in between the passageways 2l. The upper end of the valve member is tapered, as shown at 26.

'I'he vvalve seat against which the tapered portion 26 of the valvemember 22 may abut is preferably made of rubber and forms an integral part of the cup-shaped member 27 which serves the double function of sealing the valve body 22 and sealing the upper concrete plug I8 to the collar I 4. The entire cup 21 may be made of live rubber but is preferably so constructed that the cen- 5 trai portion which constitutes the valve seat is harder than the rest of the cup. As best shown in Fig. 2, the central portion of the rubber cup 27 extends upwardly slightly and is fitted along the tapered portion of the passageway 20 in the 40 upper plug I8. In this way pressure of the valve body 22 against the seat tends to press the rubber between the valve body and theplug I8 thus maintaining an effective seal at that point. y

The rubber cup 2'I is provided with a flange 28 depending from the main body thereof. Since this flange is of elastic material it tends to malntain an eifective seal against the 'collar I 4 and prevent the passage of uid upwardly around the l outside of the concrete plug I8. 50

With the construction illustrated it is' obvious that as the casing I3 is lowered into the well lled" with mud or other fluid the valve will close and remain closed as long as the pressure beneath the float collar is greater than that above 55 the oat collar in the casing. Thenarrangement y may be used in cementing a well by lowering the assembly thereinto as above indicated and then pumping cement through the casing I3. As soon -as the pressure above the float collar is suicientment has hardened the entire valve assemblyinside of the collar I4 may be readily drilled out since it contains no metal.

It Will thus be apparent that while only one embodiment of the invention has been described herein, various changes may be made without departing from the spirit of the invention or the scope of the annexed claims.

I claim:

1. Apparatus for 'oating a string of casing I` into an oil well or the like and including a metallic member adapted to be made up with the4 casing, and valve means securely mounted in said member, said valve means consisting of an upper plug and a lower plug made of cementitious material, a valve body of drillable material conned between said plugs and adapted to have limited movement with respect thereto, a cup `member of non-metallic, resilient yieldable material mounted beneath the upper of said plugs and constituting a seat for said; valve body and also constituting sealing means for preventing the flow of uid upwardly between said upper cementitious `plug and' said meta lic member.`

2. Apparatus for floating astring of casing` intoV an oil well or the like and including a metallic member adapted to be made up Awith the casing, and valve means securely mounted in said member, said valve means consisting'of an upper plug and a lower plug made of cementitious material, a valve body of drillable material conned between said plugs and adapted to have limited movement with respect thereto, a cup member of non-metallic, resilientyieldable material mounted beneath the. upper of said plugs and constituting a seat for said valve body and also constituting sealing for preventingv the ilow of fluid upwardly between said upper cementitious plug and said metallic member, the arrangement being such that when the valve is seated the resilient material is pinched between the valve body and the upper cementitious plug.

3'. Apparatus for oating a string of casing into an oil well or the like and including a metallicmemberadapted to be made up with the casing, and valve means securely mounted in said member, said valve means consisting of an upper plug and a lower plug made of cementitious material, a valvebody of drillable material conned between said plugs and adapted to have limited movement with respect thereto, a cup member of non-metallic, resilient yieldable material mounted beneath the upper of said plugs and constituting a seat for said valve body and also constituting sealing means for preventing the flow of fluid upwardly between said upper cementitious plug and said metallic member, the arrangement being such that when the valve is opened the valve body is retained by said` lower cementitious plug while permitting uid to flow downwardly around the same. l

4. In oating equipment for use in oil wells or the like, a valve seat structure comprising a block of cementitious material mounted in a metallic member and having an opening therethrough anda rubber cup located on one side of said block, said cup having an opening corresponding to the opening in said block and having a flange extending away vfrom said" block and vresiliently contacting ,the metallic member to maintain a seal between Ysaid block and the member. DEAN HANES. 

